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Diffstat (limited to 'src/leveldb/table/block_builder.h')
-rw-r--r-- | src/leveldb/table/block_builder.h | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/src/leveldb/table/block_builder.h b/src/leveldb/table/block_builder.h new file mode 100644 index 0000000000..5b545bd1af --- /dev/null +++ b/src/leveldb/table/block_builder.h @@ -0,0 +1,57 @@ +// Copyright (c) 2011 The LevelDB Authors. All rights reserved. +// Use of this source code is governed by a BSD-style license that can be +// found in the LICENSE file. See the AUTHORS file for names of contributors. + +#ifndef STORAGE_LEVELDB_TABLE_BLOCK_BUILDER_H_ +#define STORAGE_LEVELDB_TABLE_BLOCK_BUILDER_H_ + +#include <vector> + +#include <stdint.h> +#include "leveldb/slice.h" + +namespace leveldb { + +struct Options; + +class BlockBuilder { + public: + explicit BlockBuilder(const Options* options); + + // Reset the contents as if the BlockBuilder was just constructed. + void Reset(); + + // REQUIRES: Finish() has not been callled since the last call to Reset(). + // REQUIRES: key is larger than any previously added key + void Add(const Slice& key, const Slice& value); + + // Finish building the block and return a slice that refers to the + // block contents. The returned slice will remain valid for the + // lifetime of this builder or until Reset() is called. + Slice Finish(); + + // Returns an estimate of the current (uncompressed) size of the block + // we are building. + size_t CurrentSizeEstimate() const; + + // Return true iff no entries have been added since the last Reset() + bool empty() const { + return buffer_.empty(); + } + + private: + const Options* options_; + std::string buffer_; // Destination buffer + std::vector<uint32_t> restarts_; // Restart points + int counter_; // Number of entries emitted since restart + bool finished_; // Has Finish() been called? + std::string last_key_; + + // No copying allowed + BlockBuilder(const BlockBuilder&); + void operator=(const BlockBuilder&); +}; + +} // namespace leveldb + +#endif // STORAGE_LEVELDB_TABLE_BLOCK_BUILDER_H_ |